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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast cancers often contain different clones of tumor cells. Attention to the cellular properties of breast cancer metastases may identify characteristics in primary tumors that are associated with metastasis. Such characteristics could include DNA content, cell proliferation, abnormal oncogene expression, or relative cell population (clonal dominance). We examined DNA ploidy (image analysis), proliferation index (proliferating cell nuclear antigen-1 immunostaining), and expression of Her-2/neu oncoprotein in 17 invasive breast cancer samples (36 primary tumor samples) and 82 corresponding regional metastases. In all samples the primary tumor was multiclonal (usually biclonal) by DNA ploidy analysis. In approximately 90% of metastatic DNA clones (30 of 34) the corresponding clone was identified in a primary tumor sample representing 25% or more of the tumor cell population (significant clone). A majority DNA clone (> or = of tumor cell population) existed in 60% (21 of 36) of primary tumor samples and in 70% (60 of 82) of metastases (30% diploid v 70% nondiploid in both groups). In approximately 50% of metastases (37 of 82) an unexpected majority clone was identified (not a majority in any primary tumor sample) and the ratio of diploid to nondiploid clones also was 30% to 70%. However, in 80% of majority metastatic clones (46 of 60) that clone was a significant primary tumor clone. Proliferation index was quite variable in primary tumor samples and in corresponding metastases. Overexpression of Her-2/neu oncoprotein in the primary tumor of seven of 10 patients also was identified in all corresponding metastases in five of seven patients and in some metastases in two of seven patients. The metastases in three Her-2/neu-negative patients were all negative. We conclude that (1) DNA clones are stable after metastasis, (2) clonal majorities in metastases reflect clones identified in primary tumors, (3) different metastatic clones from an individual tumor can establish clonal majorities, (4) neither diploid nor aneuploid cells have a metastatic advantage in breast cancer, (5) proliferation indices are heterogeneous, and (6) overexpression of Her-2/neu is usually consistent between primary tumors and corresponding metastases.
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PMID:Breast cancer heterogeneity: evaluation of clonality in primary and metastatic lesions. 786 51

In a retrospective study, paraffin-embedded tissues from 110 primary T1 breast carcinomas (tumour diameter < or = 2 cm) were examined for the presence of the Her-2/neu encoded oncoprotein p185neu, using an immunohistochemical technique. Primary surgical therapy revealed no node involvement in 76 cases. These patients did not receive an adjuvant systemic therapy. 25% of tumours were positive for p185neu. Expression of the oncoprotein was inversely correlated to oestrogen receptor status (p < 0.05). In patients with lymph node metastases and poorly differentiated tumours, the incidence of p185neu was higher than in node negative and/or well differentiated carcinomas. However, this finding was statistically not significant. No correlations were found between the detection of the oncoprotein and age, menopausal and progesterone receptor status. The median follow-up is 85 months. In patients without lymph node metastases (n = 76), presence of the oncoprotein was significantly correlated to a shorter relapse-free and/or overall survival (p < 0.05). No such correlation was found for 34 patients with lymph node involvement. Expression of p185neu seems to mark a group of T1N0 breast cancer patients, which is at high risk and might benefit from an adjuvant therapy.
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PMID:[Expression of the p185neu oncoprotein indicates an unfavorable prognosis in small, node negative breast cancer without systemic adjuvant treatment (T1N0)]. 790 Nov 11

Nineteen paraffin-embedded breast cancer tissue samples selected for long survival (more than 5 years) were analysed for detecting the amplification of the c-erbB-2 (Her-2/neu) oncogene by Polymerase Chain Reaction (PCR). Strong correlation was elucidated between c-erbB-2 amplification and survival; such correlation was also observed with histopathologic types and nuclear grading. Because of the similarity of the breast and ovarian cancer in the etiology of the diseases, amplification of c-erbB-2, c-myc and Ki-ras genes was examined in 32 ovarian carcinoma samples (stage I-IV). In ovarian carcinomas c-erbB-2 amplification occurred in 34% (11/32) of the fresh tumour samples, and correlation between amplification and clinical staging at P < 0.05 significance level was observed. Amplification of c-myc was detected in 9% (3/32) and none of the tumours showed amplification of Ki-ras.
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PMID:Oncogene patterns in breast and ovarian carcinomas. 790 45

Amplification of genomic DNA encoding oncogenes such as HER-2 (syn.c-erbB2/c-neu) may be substantially involved in the initiation and progression of breast cancer. In order to refine and facilitate the quantitative analysis of HER-2 amplification in breast cancer, differential polymerase chain reaction (PCR) was performed on DNA derived from single cryosections of tumor tissue. This technique is based on the simultaneous amplification of a potentially amplified oncogene (HER-2) and a reference gene (IFN-gamma). Differential PCR yielded reproducible results that were in agreement with gene copy quantification using the dot blot technique. Thus we suggest differential PCR to be a reliable and rapid method for determining relative gene dosage in a minute amount of tumour tissue.
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PMID:Detection of HER-2 oncogene amplification in breast cancer by differential polymerase chain reaction from single cryosections. 790 15

One hundred and eighty thousand new cases of invasive breast cancer were diagnosed in 1992 within the United States. This disease affects approximately 1 out of 8 women in the US. Chemotherapy and/or hormonal therapy have shown some improved disease-free and/or overall survival rates. Unfortunately, this type of therapy is not directed specifically to the malignant cells, and systemic toxicities are observed. In order to develop site-specific treatment, the biology of the disease must be understood such that certain genes or their products which are involved in the pathogenesis of the disease can be targeted. Two structurally related tyrosine kinase growth factors, the epidermal growth factor receptor (EGFR) and c-erbB-2 (neu) have been identified in human breast cancer tissue and, in many instances, may function as oncogenes. The clinical data related to these two growth factor receptors as prognostic factors for the disease have been critically evaluated. Several problems with the critical studies were identified, and solutions were proposed to clarify the conflicting results reported in the studies which have attempted to examine whether c-erbB-2 (neu), in particular, is a prognostic indicator for breast cancer. In addition, data related to the structure of, ligands for and interaction between the proteins have been reviewed and presented with respect to their role in breast cancer development. A more thorough understanding of the genetic changes which contribute to the development of breast cancer will lead to more specific and less toxic treatment for this disease.
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PMID:neu(c-erbB-2/HER2) and the epidermal growth factor receptor (EGFR) in breast cancer. 790 69

A follow-up study of 143 cases of human breast cancer for over 5 years proved that Her-2/neu oncogene overexpression is much more common in the high risk group (patients died within 5 years) in comparison with the low risk group (patients survived over 5 years). The difference between these 2 groups was statistically significant. The Her-2/neu oncogene positive rate in infiltrative ductal carcinoma was 33.3%, the lower the differentiation, the higher the positive rate. Histological typing is also related to the positive rate, comedocarcinoma (intraductal carcinoma) expresses the highest positive rate while lobular carcinoma the lowest. Selection of fixation fluid and the mastering of diagnostic criteria are also important. In the author's opinion, only membrane staining in monoclonal antibody C-erbB-2 can be recognized as truly positive. In conclusion, Her-2/neu oncogene expression can be used as a supplemental marker when considering prognosis in breast cancer.
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PMID:[Study of Her-2/neu oncogene in relation to prognosis of human breast cancer]. 790 1

Promoter elements accounting for HER2 (c-erbB-2/neu) overexpression were searched for in several human breast cancer cell lines (MDA-453, BT-474, ZR-75-1, MCF-7) known to express constitutively a 30-fold range in HER2 transcripts per gene copy. HER2 overexpressing cells showed a single prominent DNase I hypersensitive site near a conserved and hitherto unrecognized ets response element (GAGGAA), located 38 bases down-stream from the CAAT box and directly 5' of the TATA box in the human HER2 promoter. Transient transfection of HER2 promoter constructs (0.125, 0.5, and 2.0 kilobase pairs (kb)) demonstrated that the most proximal promoter region (0.125 kb) was capable of conferring up to 30-fold enhanced activity in HER2-overexpressing cell lines relative to low HER2-expressing control lines. Site-directed mutagenesis of the ets response element (GAGGAA-->GAGAGA) caused a > or = 60% reduction in promoter activity affecting at least 0.5 kb of upstream HER2 regulatory sequence. Gel-shift assays with nuclear extracts and oligonucleotide sequences spanning the 0.125-kb promoter region detected an ETS-immunoreactive complex, present most abundantly in cells overexpressing HER2, whose high-affinity binding depended on the GAGGAA response element. Methylation interference confirmed the ETS-specific pattern of protein binding by this complex to guanine bases in the ets response element. UV cross-linking and immunoprecipitation implicate a approximately 60-kDa ETS protein, and candidate ETS genes expressed in these breast cancer cells include GABP alpha, elk-1, elf-1, and PEA3.
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PMID:Binding of an ETS-related protein within the DNase I hypersensitive site of the HER2/neu promoter in human breast cancer cells. 791 92

The c-erbB-2 oncogene is frequently amplified and overexpressed in human breast cancer. We have studied the c-erbB-2 protein in conjunction with DNA content in frozen samples from breast cancers using flow cytometry. The cell suspensions were obtained by mechanical disaggregation followed by a short fixation in 1% paraformaldehyde. The level of c-erbB-2 expression was calculated as a fluorescence index, taking into account the relative amount of total cellular fluorescence compared to nonspecific fluorescence. The flow cytometric value correlated with immunohistochemical results obtained with the same monoclonal antibody (c-neu, clone 9G6). Overexpression of c-erbB-2 was significantly more frequent in DNA aneuploid tumors than in DNA diploid ones and correlated with increasing S-phase fraction and estrogen receptor negativity. In 10 DNA multiploid tumors, the different aneuploid stemlines uniformly expressed c-erbB-2, supporting the hypothesis that overexpression is an early event in breast cancer. Of the 172 tumors, the 37 (22%) judged as positive with immunohistochemistry showed a somewhat higher rate of distant recurrence than others (P = 0.14). The fluorescence index was significantly associated with prognosis (P = 0.0012), as it was also among the immunohistochemically positive cases. If the degree of overexpression is important, then flow cytometry could be a feasible technique for classification.
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PMID:Simultaneous analysis of c-erbB-2 expression and DNA content in breast cancer using flow cytometry. 792 85

Amplification of the Neu/c-erbB-2 receptor tyrosine kinase has been implicated as an important event in the genesis of human breast cancer. Indeed, transgenic mice bearing either an activated form of neu or the wild-type proto-oncogene under the transcriptional control of the mouse mammary tumor virus promoter-enhancer frequently develop mammary carcinomas (L. Bouchard, L. Lamarre, P. J. Tremblay, and P. Jolicoeur, Cell 57:931-936, 1989; C. T. Guy, M. A. Webster, M. Schaller, T. J. Parson, R. D. Cardiff, and W. J. Muller, Proc. Natl. Acad. Sci. USA 89:10578-10582, 1992; W. J. Muller, E. Sinn, R. Wallace, P. K. Pattengale, and P. Leder, Cell 54:105-115, 1988). Induction of mammary tumors in transgenic mice expressing the wild-type Neu receptor is associated with activation of the receptor's intrinsic tyrosine kinase activity (Guy et al., Proc. Natl. Acad. Sci. USA 89:10578-10582, 1992). Here, we demonstrate that activation of Neu in these transgenic mice occurs through somatic mutations located within the transgene itself. Sequence analyses of these mutations revealed that they contain in-frame deletions of 7 to 12 amino acids in the extracellular region proximal to the transmembrane domain. Introduction of these mutations into a wild-type neu cDNA results in an increased transforming ability of the altered Neu tyrosine kinase. These observations suggest that oncogenic activation of Neu in mammary tumorigenesis frequently occurs by somatic mutation.
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PMID:Novel activating mutations in the neu proto-oncogene involved in induction of mammary tumors. 793 22

Both epidermal growth factor receptor (EGFR) and HER-2/neu (neu) have been found to be of prognostic importance in epithelial ovarian and endometrial carcinoma, but alterations in proto-oncogene expression of normal tissues of patients with gynecologic malignancies are unknown. Patients (118) undergoing laparotomy for gynecologic indications (78 ovarian cancer, 11 endometrial cancer, 19 benign gynecologic disease, 10 other cancers) had biopsies of normal peritoneum for quantitative assessment of neu and EGFR concentrations. Patients undergoing exploration for gynecologic malignancy were found to have significantly higher median neu expression in the peritoneal biopsies than patients with benign gynecologic disease (P = 0.002). Most patients in this study were found to have ovarian cancer, and median peritoneal neu expression was found to be significantly higher in patients with ovarian cancer versus benign ovarian masses (P = 0.0008) or any benign gynecologic disease (P = 0.004). No significant alteration of unbound EGFR was found in peritoneal biopsies of any of the groups of patients. No associations were found for a history of breast cancer, presence of ascites, or menopausal status with alteration of neu or EGFR expression in normal peritoneum. These findings of altered expression of neu in normal tissues of patients with ovarian cancer are suggestive of the presence of proto-oncogene alterations in loco-regional tissues of the peritoneum, such as might be seen if a paracrine influence existed between tumor and peritoneal cells. Alternatively, the alterations may represent subtle alterations of proto-oncogene expression of germ-line tissues.
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PMID:Growth factor expression in normal peritoneum of patients with gynecologic carcinoma. 795 83


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